Method of compressing creped paper tissue stacks at specific moisture content



Dec. 13, 1966 K M. ENLOE ETAL METHOD OF COMPRfiJSSING CREPED PAPERTISSUE STACKS AT SPECIFIC MOISTURE CONTENT Original Filed May 9, 1961 12Sheets-Sheet l Dec. 13, 1966 K. M. ENLOE ETAL 3,291,678

METHOD OF COM 35 CREPED PAP TISSUE STACKS AT CI MOISTURE C ENT OriginalFiled May 9, 1961 12 Sheets-Sheet 2 Dec. 13, 1966 ENLOE ETAL 3,291,67

METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 v 12 Sheets-Sheet 3 Dec. 13, 1966 K.M. ENLOE ETAL 3,291,?

METHOD OF COMPRESSING GREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 12 Sheets-Sheet 4 3, 1956 K. M. ENLOEETAL 3,291,678

METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 12 Sheets-Sheet 5 Dec. 13, 1966 K. M.ENLOE ETAL 2 METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS ATSPECIFIC MOISTURE CONTENT Original Filed May 9, 1961 12 Sheets-Sheet 6Dec. 13, 1966 ENLQE E L 3,291,678

METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 12 Sheets-Sheet 7 3, 1966 K. M. ENLOEETAL METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFICMOISTURE CONTENT Original Filed May 9, 1961 12 Sheets-Sheet 8 Dec. 13,1966 K. M. ENLOE ETAL 3,291,678

METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 12 Sheets-Sheet 9 i l l 12Sheets-Sheet 1O ENLOE ETAL METHOD OF COMPRESSING CREPED PAPER TISSUESTACKS AT SPECIFIC MOISTURE CONTENT Original Filed May 9, 1961 Dec. 13,1966 @Q QQ Ru kmm bukk q Dec. 13, 1966 K. M. ENLOE ETAL 3,291,678

METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 12 Sheets-Sheet 11 QQv QQQ

awm b ts QSU N para JdLL/OJU/j Dec. 13, 1966 K. M. ENLOE ETAL 3,291,678

METHOD OF COMPRESSING CREPED PAPER TISSUE STACKS AT SPECIFIC MOISTURECONTENT Original Filed May 9, 1961 l2 Sheets-Sheet 12 United StatesPatet 3,291,678 I METHOD ()FCQMPRESSlN-G CREPED PAPER TIS- SUE STACKS ATSPECEFIC MOISTURE CONTENT Kenneth M. Enloe and Le Roy L. Peterson,Neenah, Wis.,

assignors to Kimberly-(Dinah Corporation, Neenah, Wis., a corporation ofDelaware Original application lvlay 9, 1961, Ser. No. 111,417, nowPatent No. 3,172,564, dated Mar. 9, 1965. Divided and this applicationMay 15, 1964, Ser. No. 367,810 4 Claims. (Cl. 162113) This applicationconstitutes a division of our copending application, Serial No. 111,417,filed May 9, 1961, now Patent No. 3,172,564, for Manufacture ofCellulosic Products, which in turn, is a continuation-in-part of ourapplication Serial No. 19,981, filed April 22, 1960, for CellulosicProduct and Method for Making Same (now abandoned).

The invention relates to paper tissues, particularly of thetype-suitable for facial usage, and to methods for making, convertingand packing such tissues.

Facial tissues comprising creped paper sheets of a basis weight(uncreped) of about 6 to 10 pounds per ream (2,880 square feet) andusually of two-ply construction have in recent years come intoWidespread usage. Ordinarily, the tissues are boxed in a paperboarddispensing carton, and the tissues are folded in some manner Within thecarton. In one well known form, the tissues are interfolded, so thateach tissue when it is dispensed from the carton automatically bringsthe next successive tissue into easily accessible position.

Due to certain conditions, such as air entrapment between the tissues,lack of sharpness of the folds of the tissues, and the creped texture ofthe tissues with fibrous peaks of tissue being relatively upraised togive the tissues an apparent thickness greater than the actual tissuethickness, clips or stack of the tissues are quite space consuming.These conditions, particularly the amount of air entrapped and thesharpness of the folds, may also vary somewhat so that the tissue clipsvary substantially in height; and thus it is necessary that the heightof the cartons be sufficient to allow for such variability. A clip of350 plies or 175 two-ply tissues, for example, would for these reasonsrequire a relatively high carton of 3% inches in height, and a clip of400 plies or 200 two-ply tissues would require a carton about 4 inchesin height. Aged clips of 400 plies in uncompressed condition haveheights of 3 inches to 4 /2 inches, and the densities of theuncompressed tissues range from 1.75 grams per cubic inch to 2.63 gramsper cubic inch.

It has previously been proposed to compress clips of tissues so that theclips are not only more uniform in hei ht but are substantially lower inheight than prior clips of uncompressed tissues, and it has also beennoted that such compression improves the quality of the end product. Thecompression that has been found necessary varies with the moisturecontent of the tissues, a greater pressure being required for lowermoisture content and vice versa, for obtaining substantially uniformheights. Such proposals have been made in a prior application of KennethJ. Harwood, Serial No. 729,578, filed April 21, 1958 (now abandoned).The subject matter of the latter application has been included in acontinuation-in-part application, Serial No. 110,612, filed May 9, 1961now Patent No. 3,172,563, a division of which was filed on May 15, 1964,Serial No. 367,809 and now abandoned (all three applications beingcommonly owned).

In the latter Harwood application, more specifically it was proposedthat stacks of tissues be compressed approximately to 12% to 29% of theoriginal stack height. For tissues having about 6% moisture, 750 poundsper square inch pressure was proposed; while if the tissue moistures toowere approximately 4% and 10%, pressures of 1,400 pounds per square inchand 240 pounds per square inch respectively were suggested.

Compression with such pressures has been found to yield permanentlyreduced height stacks of tissue; however, we have found that the qualityof the end product may be increased still further if lower pressures areutilized. It is, therefore, an object of the present invention toprovide an improved method for compressing stacks of facial tissuesyielding a higher quality product, particularly utilizing smallercompression pressures than previously proposed. Pressures ranging fromapproximately 15 pounds per square inch to 900 pounds per square inchhave been found appropriate for stacks of tissues having a moisturecontent of 5 /z%, yielding stacks that are permanently reduced in heighta substantial amount and with tissues having a very high quality,particularly insofar as smoothness, softness and limpness are concerned.

Tissues of facial grade may be manufactured by creping the tissue from adrier drum of a papermaking machine and then calendering and stretchingthe tissue to remove again most of the creping, so as to provide adesirably soft, smooth and limp tissue. The tissue may be stored aftercalendering in the form of so-called hard rolls prior to its beingfolded by folding machines. The moisture content of the tissue, when thecompressing operation is used, is somewhat critical; and We have foundthat if the moisture content of the tissue in the hard rolls is too highor too low, the hard rolls on their exterior surfaces either losemoisture or else gain moisture with storage. Such lack of uniformityleads to non-uniformity and spoilage of some of the end product. Ifthere is an increase of moisture in the tissue, the tissue oncompression between compression members of fixed spacing becomesrelatively stiff and papery; and, on the other hand, if moisture islost, the tissue is not compressed to its desired small clip height.Thus individual hard rolls that vary in moisture content can not be runon a compressor the adjustment of which remains the same. Also, toogreat a moisture content in the tissue when it is stored in hard rollform results in compression of the tissue by itself in the rolls, thetissue becoming relatively hard and stiff, particularly at the center ofthe roll.

It is, therefore, an object of the invention to provide hard rolls forfacial tissue that is to be compressed, which rolls have such a moisturecontent that no substantial gain or loss of moisture occurs from therolls at ordinary atmospheric humidities. Such moisture content has beenfound to be about 5 percent as a compromise value.

We have also found that if the calendering and stretching above referredto are practiced on tissue having this 5 /2 percent moisture content,the moisture content has proved to be too high for successfulcalendering and unnecessary stilfness and paperiness of the tissueresults.

It is therefore another object of the invention to provide an improvedmethod for making compressed folded facial tissues which includes theuse of tissue having a relatively low moisture content in thecalendering and stretching stages and subsequently adding moisture tothe tissue, so that the hard rolls have a relatively high moisturecontent at which there is little gain or loss of moisture of the tissuein hard roll form.

Interfolded tissues for easy dispensing from a carton generally havebeen provided with tissue bonds between adjacent tissues for aiding inthe dispensing and assuring that succeeding sheets are partially pulledout of the cartons for easy accessibility, due to the particular mode ofinterfolding practiced such as is shown in the patent to Reinhardt N.Sabee, No. 2,626,145, issued January 20,1953. Interfolding may also bepracticed by longitudinally interfolding tissue webs which, however,does not provide such bonds.

It is another object of the present invention to provide interfacialbonding between adjacent sheets for use particularly with suchlongitudinal interfolding methods, as by compressing clips of thetissue, so that the tissues so interfolded without such bonds maynevertheless have sufiicient attachment to each other that the tissuesare automatically dispensed from the cartons.

The invention consists of the novel constructions, ar-

rangements, devices and methods to be hereinafter described and claimedfor carrying out the above stated objects, and such other objects, aswill be apparent from the following description of preferred methods andapparatus for practicing the invention and which are illustrated in theaccompanying drawings, wherein:

FIG. 1 is a side elevational view of the terminal end of a paper tissuemaking machine;

FIG. 2 is a view similar to FIG. 1 but on a smaller scale and indiagrammatic form and also showing a soft roll into which the paper iswound from the paper machine;

FIG. 3 is a diagrammatic elevational View of a rewinder or calendereffective on paper drawn from soft tolls;

FIG. 4 is a top view of a portion of a paper interfolder;

FIG. 5 is a perspective view of fragmentary portions of the interfolder;

FIG. 6 is a cross sectional view of a stack of paper tissues asinterfolded by the interfolder illustrated in FIGS. 4 and 5;

FIG. 7 is a perspective view of a compressing machine for compressingclips of the tissues as so interfolded;

FIG. 8 is a perspective view of a carton partially broken away to show aclip of the interfolded tissues packed therein;

FIG. 9 is a side elevational view of cutting mechanism for cutting theinterfolded tissue into clips;

FIG. 10 is a perspective view of mechanism for adding moisture to thetissue as it passes through the rewinder;

FIG. 11 is a diagrammatic illustration of a moisture sensing head whichis a part of the mechanism illustrated in FIG. 10;

FIG. 12 is a diagrammatic illustration of a part of the mechanismillustrated in FIG. 10;

FIG. 13 is a fragmentary sectional view of a portion of the mechanismillustrated in FIG. 12.

FIG. 14 is a graph showing the relationship between the pressure (P) inpounds per square inch applied on to a ZOO-ply stack of facial tissuesand the gap (G) in inches between the members performing the compressionon the tissue stack;

FIG. 15 is a graph similar to that of FIG. 14 for very small pressuresof compression;

FIG. 16 is a graph showing the relationship of tissue stifiness (S) andthe gap (G) in inches between the compressing members;

FIG. 17 is a graph showing the relationship of the bulk (B) in inches ofZOO-ply stacks of tissues with different gaps (G) in inches between thecompressing members for various tissue moisture levels;

FIG. 18 is a graph showing the variation of bulk (VB) in inches ofZOO-ply tissue stacks with the gap (G) at which compression of thetissue stacks takes place;

FIG. 19 is a graph showing the pressures for compressing the tissuesthat shall preferably be used for securing a substantial reduction inbulk without undue tissue stiffness.

FIGS. 20A and 20B are respectively perspective views of cartons withnoncompressed and compressed tissues therein, the views being disposedside by side so as to illustrate the difference in height of the cartonsusing these two types of tissues;

FIG. 21 is'an elevational view of C-folded tissues with which theinvention may be practiced; and

FIG. 22 is a perspective view of a carton packed with C-folded tissueswhich have previously been compressed in accordance with the teachingsof the invention.

Like characters of reference designate like parts in the several views.

The invention is concerned with facial tissues of the general typepreviously mentioned herein, the sheet of which have a basis weight ofabout 6 to 10 pounds per ream of 2880 square feet (drier basis weightuncreped). More particularly, it is contemplated that the basis Weightmay be about 7.6 pounds per ream. Each tissue preferably comprises twoplies of such paper sheets; and the tissues are folded, such as byinterfolding. The furnish used for the paper is bleached by conventionalprocesses so as to remove any coloring material as well as otherimpurities usually removed by such bleaching processes. In addition, nosizing is added to the furnish so that the tissues are quite absorbent,particularly in view of the light basis weight of the paper. The paperis dry creped from the drier drum of the papermaking machine and thepaper is calendered as will be more specifically described for workingthe paper fibers and surface for giving a soft, smooth and limp paperparticularly suitable for facial usage.

Referring now to the drawings, the paper converting apparatus asillustrated includes a conventional Fourdrinier type papermaking machinehaving a so-called Yankee drier drum 10 at the terminal end of themachine. A supporting frame 11 is provided for the drum 10. A shaft 12extends through the drum, and the drum is rotatably supported by meansof bearings 13 for the shaft 12 which are secured to the frame 11. Thedrum 1% is rotated by a conventionaldrive mechanism, such as a motor 14,which is drivingly connected to the shaft 12. A heating hood 15 issecured to the frame 11 and extends around the upper portion of the drum1G. Suitable hot air inlets and outlets are provided in the hood for theentry and discharge of the air or other heating medium applied to thehood.

The wet paper web to be dried is carried by a felt web 16 which travelsaround felt rolls 17. The paper web is forced against the surface of thedrum It) by a pressure roller 18 which is rotatably mounted in brackets19 secured to an arm 20. The arm is pivoted to the frame 11, and thepressure roller 18 is forced against the surface of the drum 10 by ahydraulic piston and cylinder assembly 21 that acts against the arm 20.

The paper web W is removed from the surface of the drum 10 by a doctorblade 22 which is held in contact with the surface of the drum 10 by anysuitable mounting mechanism. The web W of creped wadding from the drum10 is wound into a so-called soft rol 24 formed on a mandrel 25 which isrotatably supported on a standard 26. The mandrel 25 is driven by anysuitable driving mechanism, such as a motor 27.

In converting of tissues for cleansing or facial purposes, a so-calledrewinder 28 is utilized. The tissues are preferably made of two plies ofthe creped tissue stock; and therefore, to provide a two-ply web, tworolls- 24 are rotatably mounted in the rewinder to permit withdrawal ofthe respective webs, with one web being superpositioned on the other.The rewinder includes sets of calender rolls 29, 30 and 31, idler rolls32, and a pair of rolls 33 and 34 adapted to contact a so-called hardroll 35 of the web W which has passed through the rewinder.

The soft rolls 24 are each driven from a suitable prime mover, such asan electric motor 36; and each of the rolls 29, 30 and 31 arerespectively driven from other prime movers, such as electric motors 37,38 and 39. The roll 33 is driven by a prime mover, such as an electricmotor 40. t

A system 41 for adding moisture to the web W subsequent to its travelbetween the calender rolls 31 is provided. The system 41 includes ahousing 42 for a rotary brush 43 and having a slot 44 in its uppersurface beneath the web W. The brush 43 is driven at a contant speed byany suitable driving mechanism, such as an electric motor 45. A waterpick-up roll 46 is so positioned in the housing 42 that the bristles ofthe rotary brush 43 have a running clearance with the roll 46. A watertrough 47 is disposed beneath the roll 46. Water is maintained in thetrough 47 at a predetermined level by means of any suitable water supplyand level controlling mechanism (not shown), the water level being suchthat the roll 46 has its lower peripheral surface in the pool of waterin the trough.

The roll 46 is driven from one of the rolls 31 through a variable speeddrive mechanism 48. The drive mechanism 48 may be of any suitable typeand may comprise a drive pulley 49, a driven pulley 50, and a belt 51extending around the pulleys 49 and 50. Both of the pulleys 49 and 50are formed of opposite, separable, tapered pulley parts 52 and 53; andthe belt 51 is of the V type so that its sides match the taper of theparts 52 and 53. The parts 52 are movable axially in unison by means ofa lever 54 pivoted at 55, so that one of the parts 52 moves in onedirection while the other moves in the opposite direction.

The pulley 49 is mounted on a shaft 56 and the pulley 59 is mounted on ashaft 57. Pulleys 58 and 59, respectively mounted for rotation with thecalender roll 31 and the shaft 56, together with a belt 60, provide adriving connection to the pulley 49 from the roll 31; and pulleys 61 and62, respectively fixed with respect to the shaft 57 and the roll 46,together with a belt63, provide a driving connection from the pulley 50to the roll 46.

The lever 54 is actuated by means of an air pressure responsive motor 64comprising a piston 65 reciprocable in a cylinder 66. A spring 67 isdisposed between one end of the cylinder 66 and the piston 65.

The variable speed drive mechanism 48 is controlled by a capacitanceresponsive head 68 that is positioned in contact with the paper web Wbetween the rolls 31 and the adjacent roll 32, subsequent to passage ofthe web beyond the housing 42. The head 68 comprises a plurality ofopposite spaced plates 69 and 70 constituting a condenser 71, with theweb W between the plates of the condenser constituting the dielectric.As will be understood, the capacity between the plates 69 and 70increases with increases in the moisture in the paper web W between theplates 69 and 79. One of the plates 69 is grounded, and the other plate70 is connected to the inlet end of an amplifier '72. Another condenser73, which may be termed a reference condenser, is also connected to theinlet end of the amplifier 72. A motor 74 having an armature 75, anenergizing winding 76 and a control Winding 77 has its winding 77connected to the output end of the amplifier 72. The armature 75 isconnected by shafting 78 with the variable element of the condenser 73,and the arrangement of the motor 74 and the amplifier 72 is such thatthe armature 75 is rotated in one direction or the other so as to movethe variable element of the condenser 73 in such a direction and withsuch a degree of movement that the capacity of the condenser 73corresponds with the capacity of the condenser 71. The position of themovable element of the condenser 73 thus corresponds to .and isindicative of the capacity of the condenser 71 and thus the degree ofmoisture that exists in the web W.

The motor 74 is connected to a pneumatic controller 79 which functionsto change the air pressure in a conduit 80 connected to the cylinder 66,so as to change the speed ratio through the mechanism 48 in accordancewith changes in web moisture. The pneumatic controller 79 comprises acam 81 that is drivingly connected with the shafting 78 of the motor 74.A follower arm 82 rides on the cam 81 and is adapted to control the airdischarged from -a nozzle 83 in the end of an air conduit 84 which isconnected to a source of air pressure 85. The conduit 84 has arestriction 86 in it, and the conduit 80 is connected to the conduit 84between the restriction 86 and the nozzle 83. A bellows 87 is connectedat one end to the conduit and is fixed from axial movement on this end.The other end of the bellows is fixed to an arm 88 that is pivoted at89, and a compression spring 9% acts on the arm 88 oppositely to thebellows. The conduits 84 and 80 are flexible in the portions so indicated, so as to allow the nozzle 83 to move along with the arm 82 asit follows the cam 81.

Light responsive mechanism is used to detect breaks in the web W forautomatically reducing the speed of the roll 46 when such breaks occur.This mechanism comprises a photo-cell 91 positioned beneath the web Wand an opposite light source 92 positioned above the web W. Thephoto-cell 91 is connected by means of a conventional amplifier 93 withan electro-magnet 94 that is effective on a valve 95. The valve 95comprises a piston 96 having a circumferential groove 97 therein whichis so disposed that, when the electro-magnet 94 is de-en ergized, thevalve 95 completes the conduit 80. The valve 95 is connected to a sourceof air pressure 98; and the valve is so arranged that, when theelectro-magnet 94 is energized, the source of air pressure 915 isconnected to the motor 64 through a portion of the conduit 80.

The tissue, subsequent to being calendered in the rewinder 28, is foldedby any suitable mechanism, such as, for example, the interfoldingmechanism shown in a copen ding application of Harold V. Rutkus andCharles J. Greiner, Serial No. 837,977, filed September 3, 1959 (nowPatent No. 3,066,932, issued December 4, 1962). Basically, referring toFIG. 4, this mechanism may comprise a plurality of left-hand foldingboards 99 and a plurality of right-hand folding boards 100. The foldingboards 99 and 11113 are alternately arranged with a righthand foldingboard following a left-hand folding board and vice versa. The hard rolls35 from the rewinder 28 are cut into segments by any suitable mechanism,and the segmented hard rolls 101 are mounted on opposite sides of thefolding boards 99 and 109 by means of standards 192. The web W from thesegmented hard rolls 101 extends over an obliquely extending folding bar103 for each of the left-hand folding boards and over an oppositelyextending folding bar 104 for each of the right-hand folding boards. Theweb W then extends over a bar 165 at the head end of each of the boards99 and and underneath the boards which folds the webs so the folded webstravel in a path 196.

Each of the right-hand folding boards 191) has an inclined plane portion197 extending transversely of the path 106, an inclined plane portion108 extending parallel with the path 106, and a horizontal plane portion109 overlying the path 106. The portion 1119 is defined by a straightedge 110 extending obliquely across the path 106. The left-hand foldingboards 99 have parts 197a, 108a, 109a and 110:: corresponding to theparts 197, 198, 199 and 110 respectively of the boards 1%; but, as isapparent from the drawings, the left-hand folding boards are formedoppositely, with the parts 1118a being opposite to the parts 168 withrespect to the path of travel 106.

A cutting mechanism 111 of any suitable type is provided for cutting thetissue as folded by the boards 99 and 109. The mechanism 111, asillustrated, comprises a plurality of pressure feet 112 carried by awheel 113. A cutter knife 114 is disposed on one side of each of thepressure feet and is actuated by any suitable mechanism causing it tohave a slicing action along side of the respective pressure foot, sothat the folded tissue is cut into clips 115 of predetermined length asthe wheel 113 rotates and the knives have their slicing action. A belt116 supported by rollers 117 and a second belt 118 supported by anelongated shoe 119 are positioned respectively above and below the clips115.

The clips 115 may be compressed by any suitable mechanism, such as bythe mechanism disclosed in the copending application of Charles J.Greiner and Anthony S. Hubin, Serial No. 731,061, filed April 25, 1958(now Patent No. 2,960,023, issued November 15, 1960). Such a compressingmechanism, in brief,'may comprise a plurality of platens 120 and 121carried on upper and lower articulated chains 122 and 123. The chain 122extends around opposite sprockets 124 and 125, and the chain 123 extendsaround opposite sprockets 126 and 127. The sprockets are driven in timedrelationship to each other by any suitable mechanism (not shown) so thatthe platens 120 and 121 move along with and individually verticallydisposed with respect to each other.

A cam 128 is provided for the upper chain 122 and a cam 129 is providedfor the lower chain 123. The cams 128 and 129 are so arranged that theplatens 120 and 121 are moved toward each other as they pass between thecams. A plurality of buckets 130 are provided for holding the clips 115of tissue, and buckets are positioned at one side of the platens 120 and121 on a suitable conveyor (not shown) so that the clips may he slidfrom the buckets between opposite pairs of the platens 120 and 121.

In operation, the Fourdrinier papermaking machine functions in the wellknown manner, carrying the Web W on the felt 16 that passes over therolls 17 and 18. The web W is transferred at the roll 18 onto the drum10 and the web W is then doctored off the drum 10 by the blade 22 and iswound onto the mandrel 25 for forming the soft roll 24.

Steam under pressure is applied to the drier drum 10 for heating thedrum so as to partially dry the web W as it passes around the drum. Thespeed of the papermaking machine and the temperature of the drum 10 areso controlled that a predetermined amount of moisture remains in the webW as it leaves the drum at the blade 22. Preferably, the web W shallhave a moisture content of less than percent, and the moisture contentshall desirably be in the range of 3 to 5 percent, as the web isdoctored off the drum 10. The moisture in the web W may be determined byconventional measuring methods, such as by weighing the web prior tocomplete voiding of moisture from the web, as by heating, and subsequentto such evacuation. It will be understood that the moisture content maybe decreased by increasing the temperature of the drum and/or decreasingthe speed of the papermaking machine, while an increase in moisturecontent may be obtained by decreasing the temperature of the drum 10and/ or increasing the speed of the machine. The blade 22, as withconventional operation, crepes the web W to a certain extent as the webis doctored off the drum 10, and the creping may be on the order of 120percent, that is, the web is decreased in length by the action of theblade 22 to less than half its length when in position on the drum 10.For this degree of creping, the web W has a crepe ratio of 2.2, thecrepe ratio being the length on the drier divided by the final length.In this case, one foot of web on the drier has been longitudinallycompressed to 5 /2 inches, so that the crepe ratio is 2.2. The doctorblade 22 in its action crinkles the web in creping it, producing peaksand valleys in the web, with the peaks being relatively sharp and highcompared to the thickness of the web. The web W from the papermakingmachine is wound onto the mandrel to form the soft roll 24 forsubsequent use in the rewinder 28.

The rewinder 28 may be used either with one or more of the rolls 24simultaneously. If two plies are desired in the finished tissue, two ofthe rolls 24 are used as is illustrated. Web W is drawn from each of therolls 24 and is passed consecutively between the rolls 29, 30 and 31 andis finally wound into a so-called hard roll 35. The pairs of rolls 29,30 and 31 have a pressure nip between them so as to compress andcalender the web as it passes between the rolls. various rolls in therewinder 28, which are connected to the. motors 36 to 40, are so driventhereby that the web Furthermore, the

is stretched as it passes through the rewinder, the total stretch beingpreferably such as to decrease creping from the 2.2 ratio previouslymentioned to about 1.2 ratio. For the web having a length on the drierof one foot and shortened by creping to a length of 5% inches, therewinder stretches the web back to a length of 10 inches, so that itscrepe ratio is now 1.2 (1 foot drier length divided by 10 inches finallength), and this ratio may well vary in the range of 1.05 to 1.30within the teachings of this invention. The web has thus been againstretched, practically back into its original length. The restretchingof the web by the rewinder and the calendering action by the rolls 29,30 and 31, acting with pressure on the web as it passes between therolls, have the effect of rendering the tissue quite soft and limp, sothat the tissue has these desirable qualities for use as a facialtissue. Incidentally, practically all of the stretching, about percentof it, in such a rewinder 28 is preferably done between the soft rolls24 and the first press rolls 29, and the subsequent press rolls 30' and31 function principally as calender rolls so that the web not only issoft and limp but, in addition, has a smooth surface.

The system 41 functions to add moisture to the web W subsequent to thecalendering action of the rolls 31 and prior to the winding of the webinto a hard roll 35. The brush 43 is driven at a constant speed by themotor 45, and the brush 43 makes contact on the bristle ends with theroll 46 that functions as a metering roll. Water is maintained at aconstant level in the trough 47 with the roll 46 dipping into the poolof water, and the brush 43 in contacting the roll 46 picks up water fromthe surface of the roll 46 and throw it through the slot 44 in thehousing 42 onto the web W. The speed of rotation of the roll 46 isvaried in order to vary the amount of water picked up by the roll 46from the trough 47 and transferred onto the brush 43, thus to vary therate at which water is thrown by the brush 43 through the slot 44 ontothe web W and to vary the increase of moisture thus provided in the webW by the system 41.

The capacitance head 68 functions as a sensing unit to increase thespeed of rotation of the roll 46 if the web W is too dry, therebyincreasing the moisture applied to the web to bring its moisture up tothe predetermined desired value, and functions oppositely to reduce thespeed of rotation of the roll 46 for decreasing the amount of waterapplied to the web W when the moisture content in the web W is too high.

The head 68, as above described, includes opposite plates 69 and 70;and, if there is too little moisture in the web W, the capacity betweenthe plates is unduly low. The amplifier 72 so functions, if the capacityof the condenser 71 is too low, to correspondingly'decrease the capacityof the condenser 73 by correspondingly rotating the armature 75 of themotor 74. The rotative position of the movable part of the condenser 73is, incidentally, indicative of the relative moisture that exists in theweb W. The armature 75, in rotating, turns the cam 81 drivinglyconnected to it correspondingly and opens the nozzle 83 to a greaterextent, due to the movement of the lever 82 following the cam 81. Airunder pressure is supplied to the conduit 84; and, when the nozzle 83 isthus opened to a greater extent, the air pressure in the conduit 84between the restriction 86 and the nozzle 83 is reduced. The air underpressure in the conduit 80 connected to this portion of the conduit 84is applied onto the piston 65 in the cylinder 66 for changing the actionof the speed changing unit 48, and this reduction of air pressure in theconduit 80 allows the spring 67 to be effective to move the piston 65 tothe left as seen in FIG. 12.

The bellows 87, which is under the air pressure in the conduit 80, isunder these condition less etfective in its action counter-balancing thespring 90, so that the spring 90 returns the nozzle in close proximityto the follower 9 82, with the nozzle 83 and bellows moving about thepivot 89. Equilibrium is thus again effected between the force on thelever 88 due to the spring 90 and the force on the lever due to thebellows 87, maintaining the pressure in the conduit 80 at a certainpredetermined lower value corresponding to the rotation of the cam 81.

The solenoid 94 is assumed to be de-energized under the conditions justdescribed, and the conduit 80 is thus complete between the nozzle 83 andthe piston 65. The reduction in air pressure in the conduit 80 causesthe spring 67 to be effective to move the piston 65 and lever 54 and tomove the movable pulley parts 52 in opposite directions to decrease theeffective diameter of the pulley 50 and increase the effective diameterof the pulley 49. Assuming that the speeds of the rolls 31 and thus thepulleys 58 and 59 and the drive shaft 56 remain without change; thespeeds of the shaft 57, the pulleys 61 and 62, and the roll 46 are thusincreased. The roll 46 thus draws more water from the pond within thetrough 47, and the brush 43 removes this increased amount of water fromroll 46 and throws it onto the web W so as to increase the moisture inthe web W. Thus, the capacitance sensing head 69, in sensing a decreasedamount of moisture in the web W, is effective to control the speed ofthe roll 46 through the connecting electrical and pneumatic systems soas to increase the moisture in the web W to make up the deficiency inmoisture and return it to a predetermined value.

Conversely, if the moisture in the web W is too great, the parts of thecapacitance sensing head 68 and the electrical and pneumatic controlsystems controlled by the head 68 function oppositely to reduce thespeed of the roll 46 and thereby reduce the amount of water thrown ontothe web W by the brush 43 so as to decrease the moisture within the webW to its desired predetermined value.

The function of the photo-cell 91 is to cause a reduction in speed ofthe water pickup roll 46 if a break in the web W should occur, so thatan unduly great amount of water is not thrown off by the brush 43 underthese conditions. If the web W breaks, the photo-cell 91 is energized,and it is effective through the amplifier 93 to energize the solenoid94. The solenoid 94, when energized, moves the valve piston 96 so as toconnect the source of air pressure 98 with the motor 64 through a partof the conduit 80. The air pressure is thus increased on the piston 65and moves the piston 65 against the action of the spring 67 so as toincrease the effective diameter of the pulley 50 and decrease theeffective diameter of the pulley 49. The change speed unit 48 is thuseffective to reduce the speed of the roll 46 under these conditions.

The electrical and pneumatic portions of the moisture adding system 41are preferably so set that the brush 43 sprays just sufiicient waterthrough the slot 44 to raise the moisture content of the web W as closeto /2% as possible with the range of 5 /:%:L-1%, particularly. As willbe subsequently pointed out, however, more or less moisture may also beused, if desired, to obtain satisfactory quality compressed tissues. Forexample, the web W may be maintained at a 4% moisture level by disablingthe moisture adding mechanism 41, in which case, the increased pressureshereinafter mentioned may be utilized in using the compressor shown inFIG. 7 to obtain satisfactory tissues. The moisture in the web W mayalso be increased to much higher levels, as by means of the mechanism41, in which case the hard rolls 35 are immediately used without storageand the pressures necessary for obtaining tissue stacks compressed to acertain reduced height are less.

We have found that if the creped wadding is run through the rewinder 28with a moisture content greater than 5 percent, the web is squeezed out,stiffened and flattened due to the calendering action of the rolls 29,30 and 31. Some of this stiffening action may be due to the fact thatundue moisture content of the wadding in and of itself tends to undulyrelease the creping of the web. Sufiicient tension must be maintained onthe web in order to obtain a uniform hard roll 35, and this tension alsois effective to pull out the creping at high moisture levels of the webW. The desirable softness of the wadding is thus not obtained and thetissue is not fully satisfactory for facial uses when the web is runthrough the rewinder at high moisture levels. On the other hand, if thewadding is maintained at a relatively low moisture content of less than5% as it is run through the calender rolls 29, 30 and 31, the wadding isnot permanently compressed and stiffened, and the rewinder functions asintended, namely to smooth the tissue and render it soft and limp.

It is quite often necessary to store the hard rolls 35 prior to usage ofthem in folding the tissues. We have found that, if the hard rolls 35have a moisture content of about 5 /2%; at ordinary humidities, the hardrolls do not increase in moisture content nor decrease in moisturecontent materially. At this moisture content, the wadding is atequilibrium with the atmosphere at the usual humidities at which thehard rolls are stored and the finished tissues are used. It is desirablethat the hard rolls remain uniform as to moisture content due to thedifferences of action of later steps to be taken caused bynon-uniformities of moisture content. When the tissue is stored as ahard roll 35, it is preferable that the hard roll have a moisturecontent less than 7.5 percent, since the tissue tends to compress itselfin a hard roll, particularly at the core, and when so compressed, thetissue hardens and stiffens. Furthermore, at higher moisture content,some of the crepe is pulled out of the tissue when it is wound as a hardroll.

The hard rolls 35, which preferably have the 5 /2 percent moisturecontent, are cut into segments by any suitable mechanism and are thenmounted on the standards 102 of the interfolding mechanism. Web W passesoff of one of the rolls 101, over folding bars 103 and 105, and under aleft-hand folding board 99. The bars 103 and 105 simply function tochange the direction of motion of the Web, as is apparent. The web, inpassing under the board 99, has one half or .fold 101a of it passingunder the plane portion 107a; and the other half or fold 101b of itpasses under the plane portion 108a, under the horizontal portion 109aand across the obliquely extending edge 110a, all as is quite completelyshown in FIG. 5. The horizontal portion 109a and its obliquely extendingedge 110a thus function to fold the latter half of the web underneaththe former half that passes under the portion 107a which is in the pathof travel 106.

A right-hand folding board 100 is positioned just behind the left-handboard 99 in the path of travel 106, and the top fold 101a from theprevious board 99 is trained over the horizontal portion 109 of theboard 100. Web is folded by the board 100 in substantially the samemanner as by the board 99, except that the told is made on the oppositeside. One half or fold 1010 of the web from a roll 101 passes underneaththe portion 107 of the board 100 and is thus positioned on top of theupper fold 101a produced by the previous board 99. The other half of theweb from the roll 101, which is on the right side as seen in FIG. 5,passes under the portion 108, thence under the horizontal portion 109,and is folded under by the obliquely extending edge 110. In view of thefact that the upper fold of the web from the previous folding board 99travels over the horizontal portion 109 of the board 100, the right-handhalf 101d of the web on the board 100 is folded underneath not only theleft half 1010 of the web on the board 100, but also underneath the topfold 101a from the previous left-hand board 99. Thus, the two boardsproduce a stack of interfolded tissues having upper and lower folds 101aand 101b from the left-hand board 99, and upper and lower folds 101s and101d from the right-hand board 100, with the folds 1010 and 101d beingrespectively above and below the upper fold 101a from the board 99.

Subsequent, alternately arranged, left and right boards 99 and 100 eachfunction, as will be understood, to provide folds just below the topfold from the previous board so that a stack of interfolded tissues,such as shown in FIG. 6, having folds 101a to 161k, results.

The pressure feet 112 of the wheel 113 function to crease theinterfolded web W as the wheel 113 is rotated, and each cutter 63 isactuated when the corresponding pressure foot is positionedsubstantially vertically over the compressed bundle of tissues to cutthe tissues into clipS 115. The clips 115 of tissue have any entrappedair squeezed from them by the belts 116 and 118, which are respectivelysupported by rollers 117 and shoe 119, so that the tissue clips 115 havea nearly uniform uncompressed height.

The clips 115 are inserted into the buckets 139, and the clips are slidfrom the buckets between the platens 120 and 121 of the compressor shownin FIG. 7. The chains 122 and 123 are driven, and the platens 120 and121 are moved toward each other due to the action of the cams 128 and129 as the chains move, in order to compress the clips of tissue. Thetissue clips 115 are removed from between the platens in substantiallycompressed condition after the clips pass beyond the cams 128 and 129and the clips 115 are then packed into dispensing cartons 131, each ofwhich has a slot 132 on its upper face through which the tissues may bewithdrawn one at a time. In view of the fact that the tissues areinterfolded, the withdrawal of the top tissue causes the tissueimmediately therebelow to be partially drawn through the slot so that itmay be easily grasped for usage. The cartons 131 are made of paperboardand, as shown, are in the form of boxes having rectangular sides, topand bottom.

The compressing machine illustrated in FIG. 7 thus functions to compressthe tissue clips 115, leaving them with a height substantially less thantheir uncompressed height. Although the illustrated apparatus and methodmay obviously be used with clips 115 containing many different numbersof tissues; as an example, the apparatus and method permit the packingof 350 tissue plies or 175 two-ply tissues into a 2-inch high boxallowing a substantial air space between the top of the clip and the topof the box 131. Such a clip prior to compression has a height of about2.6 inches, and the compression step reduced the height of the clip justafter compression to about one inch. Assuming a tissue moisture contentof /2 percent, the cams 128 and 129 in the compressor illustrated inFIG. 7 may be so set as to compress the clips 115 from the 2.6 inchheight to inch; and the speed of the machine, although this is notcritical, may be such as to maintain the tissues so compressed for aboutone second. Such a compression corresponds to 440 pounds per squareinch. As the platens 120 and 121 pass beyond the cams 128 and 129 so asto release compression on the clips, the clips re-expand from /8 inch tothe one inch height. The clips are then put into their boxes 131, and itis contemplated that the tissues shall be stored as so packed for apredetermined length of time prior to usage, such as for a period of atleast two weeks.

As has been previously described, the actions of the doctor blade 22 increping the tissue from the Yankee drier drum to a 2.2 crepe ratio, forexample, and the subsequent elongating of the tissue by the rewinder 28for taking out most of the creping of the tissue results in a relativelysoft limp tissue. The creping, however, produces a myriad number ofsharp peaks in the paper which remain. The clips 115 in being compressedbetween the platens 120 and 121 have these peaks dulled or depressed sothat the tissues are in effect smoother sheets and are thus of higherquality for facial use. The tissue thu in eifect has an improved feelfor use as a facial tissue due to the compression. The sheet thus isworked not only by the doctor blade in creping, the rewinder 29 instretching the tissue and calendering it, but also by the compressorillustrated in FIG. 7 in compressing it.

During the storage period for the tissues after packaging in the boxes131, the clips re-expand to some extent, such as to 1% inch to 1% inchfor the 350 ply clip previously mentioned. Although the moisture contentof the tissues has been brought to 5 /2 percentil percent as previouslymentioned by the moisture adding mechanism 41, which is that moisturecontent that remains substantially the same in the humidities commonlyencountered in which the tissues are used and the hard rolls 34 arestored, nevertheless, the actual height to which the tissues re-expandin this storage period varies principally due to the differentatmospheric humidities in which the tissues are stored for this period.If the humidity is about 75 percent, for example, the increase in heightof the packaged clips will be to about 1% inch while if the humidity isquite low, the tissues may re-expand to only the 1% inch height (thislatter re-expansion during storage is considered abnormally low). It isquite desirable that the tissues shall not re-expand to the full 2 inchheight of the box, since initial dispensing of the tissues would thus bemade relatively difficult. It is contemplated that the tissues onre-expansion during storage in the cartons for an indefinite length oftime, such as two weeks or a month, shall not have an uninhibited heightmore than the height of the cartons and shall preferably have a heightsomewhat less than carton height so that the tissues may dispense easilyand do not bulge the tops and bottoms of the cartons.

The compression step by the machine illustrated in FIG. 7 has thefunction of jamming the fibers on the faces of the tissues together sothat the fibers interlock to some extent to thus form interfacial bonds.The initial reexpansion, just after compression between the cams 128 and129, has the effect of breaking some of these interfacial bonds withaccompanying breakage of some of the fibers on the faces of the tissues.One by one the fibers break loose from each other on contacting sheets;and as one fiber breaks, it releases more force on a next one so that itbreaks, and this process continues until the tissues are not so closelyassociated. During the two weeks storage period this process continues,the fibers on the surfaces of the tissues being broken to some extentwith an accompanying lessening of the interfacial bonding. Thisreduction of interfacial bonding and breakage of surface fibers has theelfe-ct of increasing the bulk and rendering the tissue more limp. Bothof these qualities are desirable in a facial tissue, and thus it ispreferable that this storage take place prior to usage, in order thatthe tissues may not be of relatively low bulk and relatively stiff. Inthis connection, although the tissues may be used as single plies,preferably the two-ply tissue is used, since a twoply tissue tends to bemore soft and less stilf than a single ply tissue. The basis weight ofthe tissues is not considered critical, however, in actual usage a 7.6basis weight (uncreped) per ream (2800 square feet) has been use As hasbeen previously mentioned, the moisture content of the tissues justprior to compression is preferably maintained at 5 /2 percent and in therange of 5 /2 percent i1 percent, which is a compromise moisture contentcorresponding to the humidities of the air in which the paper beforecompression is generally stored. In this connection, it may be mentionedthat in order to obtain the ultimate uniform compressed clip heightsdesired, the action of the compressor as illustrated in FIG. 7, andparticularly the distances between the cams 128 and 129, shouldpreferably be changed with changes in moisture content; with a greaterpressure being applied to the clips at the low end of the range, at 4 /2percent moisture content, as compared to the pressure at the high end ofthe range, 6 /2 percent moisture content.

Various carton heights may be used with the compressed tissues of theinvention. For example, 200 tissue plies may be packed into a 1% inchhigh carton, 400 plies may be packed into a 2% inch high carton, and 600plies may be packed into a 3 /2 inch carton.

Assuming that the compression is performed with tissues having thepreferred moisture content of 5.5 the following table indicates, as anexample, the gap in inches between the platens 120 and 121 and thecorresponding pressures applied to the tissue stacks for packing thetissues in various sized cartons with the tissue stacks being packedsufiiciently loosely in the cartons for easy dispensing, even assumingthat the filled cartons are stored at high humidities, such as 75percent, causing a relatively large growth of the tissue stacks afterpacking. The gaps between the platens on the basis of 200 plies orindividual sheets (100 two-ply tissues), in each case, is alsoindicatcd:

Of course, the paper furnish used for the tissues and also other factorsmay vary, so that actually a variation of is contemplated with respectto the pressures above listed. In the above example, the various gapsare particularly applicable to tissue clips, weighing about 328 gramsfor 400 plies in bone dry condition. The sheets when folded have about42 square inches surface area and are about 8% inches by 9% inches. Thethickness of the particular tissues used was about .004 inch.

The relationship between the gap of the platens in compressing thetissue stacks (on the basis of 200 plies) and the pressure therebyapplied by the platens is shown by the graphs of FIGS. 14 and 15. Itwill be observed that the pressure varies widel at high pressures andrelatively small gaps and varies relatively slightly at relatively largegaps and small pressures.

Although the invention is preferably practiced with the tissue moisturebeing at 5.5% or thereabouts, the same end bulk of the tissue stacks maybe obtained at Other moistures. For example, at 4% moisture and at 10%moisture contents of the tissue, the following gaps and pressures may beutilized to obtain the same bulk of the compressed tissue stacks:

The quality of the tissues is indicated approximately by an arbitrarymeasure of stiffness such as is shown in the ordinates of FIG. 16. Thisfigure shows the relationship between the gap G in inches of the platensfor a ZOO-ply tissue stack and the resulting stiffness of the tissues.Using the stiffness scale of the graph, a stiffness above three may beconsidered generally objectionable for facial tissues, while stiffnessesbelow three are satisfactory. Stiffnesses below 2 or 2.5 are verysatisfactory. It will be observed from the graph that for very smallgaps, the resulting tissue stiffness rises above three, and hence thesegaps with the resulting high pressures would be objectionable. As isapparent from the graph, larger gaps (and hence smaller pressures) areusable with higher moisture contents for obtaining the same stiifnesses.

In order for the stacks of tissues to remain permanently compressed sothat there is a substantial saving in space,

substantial pressures (at gaps that are substantially less than theinitial uncompressed height of the stacks) should be used. FIG. 17 showsthe relationship between the gap in inches and the ultimate bulk orheight of a ZOO-ply tissue stack. The bulk was measured at the end of 14days after compression and after storage of the stacks at a highrelative humidity of As will be observed, as an example, if the gap is/2 inch for stacks at a moisture of 10%, the bulk is reduced from about2 inches (uncompressed) to about 1.2 inches. Likewise, other readings ofeventual bulk may be obtained from the FIG. 17 graph.

FIG. 18 shows the variations in bulk of stacks of 200- ply tissues thatmay be expected for various compressed conditions depending on the gapused during compression. For example, if a one-inch gap is used, thevariation in height of a number of stacks at the end of 14 days is aboutinch. On the other hand, the variation in height of uncompressed stacksis inch. Since the variation is so much less for compressed stacks ascompared to uncompressed stacks and is less if the gap is decreased, itwill be understood that packing of the stacks after compression may bein smaller sized cartons that need not provide for large variations oftissue bulk.

A stiffness rank above approximately three is generally consideredundesirable for facial tissues; and it will be understood that, in orderto make the compression step economically worthwhile, a substantialultimate reduction in issue bulk should be obtained. A reduction in bulkfrom about 2 inches to 1.75 inches (for a 200- ply tissue stack,referring to FIG. 17), for example, makes the compression stepeconomically desirable. The gaps that should be used are below .90 inch,.70 inch, and .63 inch corresponding to relative humidities of 10%, 5.5%and 4% at the ultimate bulk of 1.75 inches as is apparent generally fromFIG. 17. On the other hand, referring to FIG. 16, it is obvious that ifthe gaps are too low, undue stiffness of the tissues results. Forstiffnesses below three, the gaps should be greater than about .42 inch,.300 inch and .27 inch which correspond respectively to 10%, 5.5% and 4%moisture levels. For a moisture content of 4%, the gap per 200 tissueplies should preferably be between .27 inch and .63 inch; for a moisturecontent of 5.5%, the gap should be between .300 inch and .70 inch; andfor a moisture content of 10%, the gap should be between .42 inch and.90 inch. The corresponding -pressures of compression in pounds persquare inch are approximately 1350 to 28 for 4% moisture; 890 to 15 for5.5% moisture; and 140 to 4 for 10% moisture, the graphs of FIGS. 14 and15 showing generally the relationship between compression pressure andgap.

Corresponding desired limits of pressure exist for the other tissuemoistures at which compression may take place. These limits are setforth in the graph of FIG. 19. In addition to the pressure limits abovementioned, it will be observed from the FIG. 19 graph that the desirablepressure limits are approximately (in pounds per square inch) 18. to1000. for 5% moisture; 12.5 to 720. for 6% moisture; 9. to 500. for 7%moisture; 7. to 340. for 8% moisture; 5. to 220. for 9% moisture, and 3.to for 11% moisture.

Compression of tissues according to the invention has been found toproduce clips or stacks of tissues that have a bone dry density between2.75 grams per cubic inch to 3.95 grams per cubic inch. These densitiescorrespond to 278 to 400 thicknesses of the tissue paper per inch. Itwill be understood that there are twice as many thicknesses in a certainclip or stack of tissues as there are plies or sheets in view of thefact that each tissue of two plies and each sheet has been folded over.These values of thicknesses per inch and density are applicable to clipsof tissues which have freely expanded within their cartons during anindefinite storage time, such as of 2 weeks or longer. Each of thetissue stacks within the cartons, it will be understood, as anuninhibited height which is the same or less than the internal height ofthe carton, so that the tissues may be freely dispensed and so that theydo not cause bulging of the carton. These thicknesses per inch anddensities allow the use of an Tissues Thick- Carton Clip Thick- Density(2-Ply) Plies nesses Height Height nesses (gr./cu.

(Inches) (Inches) per Inch in.)

100 200 i 400 1% 1-1 As 400-278 395-2. 75 200 400 800 2% 2?% 400-3553.95-3.51 300 600 1 1,200 3% 34% 400-343 3.95-3.39

Referring to the above table, in explanation, the number of plies listedare the number of sheets that are in the clip which is packaged in theparticular size of carton that is listed under carton height. Eachindividual tissue contains two plies so that the number of tissues ishalf the number of plies. The clip heights listed in the above table arethe heights of the clips within their cartons after the re-exp-ansionthat takes place during an indefinite storage time, such as, forexample, of two weeks or longer. The column entitled thicknesses liststhe total number of thicknesses in each clip which is twice the numberof sheets or plies due to the fact that each tissue is folded over onitself in the clip. In the column entitled thicknesses per inch, thenumber of thicknesses per inch of clip height after this re-expansionare indicated. It will be observed that the number of thicknesses ofpaper per inch of clip height varies from 400 to 278. The density of there-expanded clips is in the Density column of the table and is in gramsper cubic inch. It is to be noted from the table that the densities varyfrom 2.75 grams per cubic inch to 3.95 grams per cubic inch. The tissuestacks, according to the table, have heights (the stacks beingunrestrained and exerting substantially no pressure on their cartons)from 1 inch to 1 inches, 2 inches to 2 inches and 3 inches to 3 /2inches, respectively. The densities are given for the paper in bone drycondition and if measurements of these tissues are made at variousmoisture contents, the densities measured, of course, will be greater.For example, in lieu of the densities between 2.75 and 3.95 grams percubic inch, the densities will range between 2.91 grams per cubic inchto 4.19 grams per cubic inch at 6 percent moisture content. The moisturecontents are on the basis of weights, the weight of a clip including theweight of the moisture being used as the basis. 6% moisture content, forexample, indicates that the moisture by weight amounts to 6% of theweight of the clip prior to removal of moisture therefrom. Although thefigures given in this table are considered important regardless ofvariations in basis weight and crepe ratio, they are consideredparticularly important for a final crepe ratio of about 1.2 and a drierbasis weight of about 7.6 pounds per ream of 2880 square feet.

The interfolded tissues are used by withdrawing them one by one from thecarton 131 through the slot 132 in the top of the box. The withdrawal ofone tissue automatically draws the top fold of a following tissuepartially through the slot 132 so that the succeeding tissue is easilyaccessible. The interfacial bonding which exists between adjacent tissuefolds due to the compression assures that the succeeding sheet will bedrawn through the slot 132, and this interfacial bonding is particularlyimportant in connection with interfolding of the type illustrated inwhich there are no bonds of tissue between adjacent tissues.

Our improved method of manufacturing tissues provides boxed clips oftissue that have a substantially uniform height which is less thanprevious uncompressed clips of tissue. Three hundred fifty ply clips mayeasily be packed int-o a 2 inch high box with sufficient space remainingbetween the top of the clip and the top of the box, so that the tissuesmay be readily withdrawn through the slot in the box. Such a quantity oftissue previously, without compression, would have required a box ofabout 3% inches high. There is thus, for the same number of tissues, aconsiderable saving of space, not only on dealers shelves, but alsoinvehicles used in transporting the tissues, with consequent monetarysavings.

The tissues manufactured in accordance with our improved methodsfurthermore are of improved quality as compared to prior tissues. Thetissues made according to our invention are desirably soft and limp, andthey are smoother than prior uncompressed tissues, due to the fact thatthe sharp peaks produced by the creping have been dulled or depressed bythe compression. The uninhibited re-expansion of the tissues withintheir cartons allowed by the diiference in height between the clips andcartons during the storage period of the clips after packaging andcompression results in softer tissues; and, although the peaks due tothe creping tend to again rise with the release of interfacial bondingthat occurs during storage, the original condition of the high peaks ofcrepe is never again reached, so that the tissues remain smoother.

Due to the fact that the tissue is preferably passed through therewinder 28 with a relatively low moisture content, the undesirablestiffness and paperiness that would occur if the tissue had a relativelyhigh moisture content when passed through the rewinder are not obtained.Nevertheless, the relatively high moisture content of 5 /2 percent :1percent desired in the hard roll exists due to the additional moistureadded subsequent to calendering, and thus large variations of moisturecontent throughout the hard roll or the hardening and stiffening of thetissue in the hard roll, particularly at the center of the roll, do notexist.

The compression of the tissue clips has the effect on the tissues ofproviding interfacial :bonding which is particularly advantageous whenthe tissues are interfolded by an interfolder of the type that does notprovide any tissue bonds between adjacent sheets. The interfacialbonding exists even after prolonged storage periods and assures thatleading portions of succeeding tissues are drawn through the slot in thetop of the box, so that the succeeding tissues are easily available. Thedry creping operation tends to raise lint in the tissues apparently bysplintering fibers loose from the body of the web, and the compressionoperation has the advantageous function of rebonding the linty fibersback into the body of the tissues, so that the latter become less linty.

FIGS. 20A and 20B illustrate the advantages of the present invention.The same number of tissues may be packed in and occupy a carton 200which is only slightly more than half the size of a carton 201 for theoriginal uncompressed tissues. For example, in lieu of a 4 inch highcarton for 200 2-ply tissues, a 2% inch high carton is satisfactory. Theslack fill that occurs as a general rule and which is quite variable, inconnection with the uncompressed tissues, as illustrated in FIG. 20A, isovercome; and only a slight spacing, such as of A inch or less, may beused satisfactorily in connection with the compressed tissues as isillustrated in FIG. 20B.

As is apparent, the invention may also be utilized in connection withtissues which are folded in some configuration other than interfolding.The invention is illustrated in FIGS. 21 and 22 in connection withC-folded tissues 202, FIG. 21 illustrating an uncompressed stack 203' ofsuch C-folded tissues which are each preferably of two plies similar tothe interfolded tissues previously described. Each of these tissues hasa central base portion 202a and has side edge portions 202]; and 202::which are folded over the central portion 202a and have a space 292dbetween them. The base portion 202a may, for

1. IN A METHOD OF MAKING PAPER TISSUE, THE STEPS WHICH COMPRISE, CREPINGPAPER TISSUE FROM THE DRIER DRUM OF A PAPERMAKING MACHINE WITH THE PAPERTISSUE HAVING A MOISTURE CONTENT OF LESS THAM 5 PERCENT, CALENDERING ANDSTRETCHING THE CREPED TISSUE SO AS TO REMOVE SOME OF THE CREPING, ADDINGMOISTURE TO THE TISSUE SUBSEQUENT TO SAID STRETCHING AND CREPING TOINCREASE THE MOISTURE TO TENT TO 51/2 PERCENT $1 PERCENT, ANDSUBSEQUENTLY WINDING THE TISSUE INTO A ROLL.
 3. THE METHOD OF MAKINGSTACKS OF CREPED TISSUE PAPER OF BASIS WEIGHT (UNCREPED) OF ABOUT 7.6POUNDS PER 2,880 SQUARE FEET AND HAVING A CREPE RATIO OF ABOUT 20PERCENT, THE PAPER BEING MADE OF BLEACHED FURNISH TO WHICH NO SIZING ISADDED AND WHICH IS DRY CREPED AND CALENDERED, COMPRISING THE STEPS OFFOLDING SHEETS OF THE CREPED TISSUE PAPER HAVING A MOISTURE CONTENT OFABOUT 51/2 PERCENT INTO STACKS, COMPRESSING SUCH STACKS IN THE DIRECTIONPERPENDICULAR TO THE PAPER UNDER A PRESSURE BETWEEN 15 AND 890 POUNDSPER SQUARE INCH, AND THEREAFTER RELEASING THE STACKS FROM SUCHCOMPRESSION TO THEREBY FORM STACKS WHICH ARE SUBSTANTIALLY LESS INHEIGHT THAN THE ORIGINAL HEIGHT OF THE STACKS BEFORE COMPRESSION AND INWHICH THE SHEETS ARE SOFT AND SMOOTH AND LIMP.